A method for arranging a local reinforcement in a thermoplastic sandwich plate is known in the specialist field, for example from European Patent Application EP0 383 409. The method which is known from that application comprises arranging a local reinforcement in a thermoplastic sandwich plate by injection-moulding a thermoplastic into the sandwich plate. To arrange a securing point in the local reinforcement, it is possible for a metal insert to be arranged in the still-liquid injection-moulded plastic, as is described in more detail in EP0 671 992.
Another method for arranging a plastic insert unit in a sandwich plate having at least one thermoplastic fibre-reinforced covering layer is known in the specialist field, for example from U.S. Pat. No. 5,437,750. The method which is disclosed in that document comprises placing and bonding a plastic insert unit in a sandwich plate, comprising two fibre-reinforced thermoplastic covering layers which are adhesively bonded to a core layer comprising a multiplicity of strips of aramid paper or another thin-lightweight material, which are adhesively bonded and deformed in such a manner that an array of honeycomb cells is formed. This method comprises drilling a hole through the sandwich plate, placing a thermoplastic insert unit in the hole and then fusing the thin sides on top of the plastic insert unit to the fibre-reinforced thermoplastic covering layers by the application of ultrasonic energy.
Another method which describes the welding of a thermoplastic insert unit into a sandwich plate comprising fibre-reinforced thermoplastic covering layers adhesively bonded to a honeycomb is presented in U.S. Pat. No. 5,536,344. This method describes arranging a plastic insert unit by means of rotation welding.